1. Field of the Invention
The present invention relates generally to apparatus for dissolving solids in liquids, and in one of its aspects, to a chlorinator for dissolving chlorine solids in water for swimming pools.
2. Description of the Prior Art
Adding chlorine to swimming pool water is highly desirable in order to prevent the buildup of fungus and bacteria in the water. In the past, those in charge of swimming pool maintenance would dump liquid chlorine directly into the pool on a periodic basis or as determined by various checking procedures. Over the years, the demand for an automated way of chlorinating swimming pool water increased leading to the development of pool chlorinators or "feeders."
A conventional pool chlorinator includes a tank for holding chlorine solids usually in the form of chlorine tablets, an intake line connecting the water line at the high pressure side of the pump to the tank, and a return line connecting the tank to the water line on the low pressure side of the pump. The difference in pressure between the high pressure side of the pump and the low pressure side of the pump forces the water through the tank over the exposed surface of the clorine solids, dissolving the solids. A ball cock type mechanism is frequently used to control the water level within the tank, the ball cock valve shutting off the intake line when a certain water level is reached within the tank. Frequently, the tablets are inserted into the tank in an enclosed plastic container. The user in supposed to punch holes in the container to allow the water to circulate through the container over the exposed surface of the chlorine tablets. The rate at which the chlorine tablets are dissolved is partially dependent upon the number and height of the holes punched in the tablet container.
A number of problems arise with the use of a conventional chlorinator. One serious problem is caused by the return line returning the water from the tank to the water line on the low pressure side of the pump. This arrangement causes water with a high concentration of chlorine to be pumped through the pump and filter causing serious corrosion of both. Further, because of the relatively fixed water level within the tank and the fixed size of the chlorine tablet container, the rate of dissolving the chlorine solids cannot be adjusted over a large range. There is, therefore, no way to make allowances for different pool sizes and conditions using a single size chlorinator except for the small adjustments that can be made to the ball cock or in the holes made in the chlorine tablet container. The efficiency of the conventional chlorinator is also limited since the intake to the chlorinator is taken from the most heavily chlorinated water in the water line, the intake line connecting to the water line downstream of the return line.